Blinking ses light at WOT

[ssms5411]

No, no other symptoms, just a hard start when cold, have to hit the gas pedal to get it to stsrt and idle but when warm it starts fine. I really think my fuel pressure is good since I dont go lean or anyyhing on my wideband.

[ssms5411]

Fuel pressure is good, heres a couple of pics of the gauges. Will find out tomorrow if I have a blinking light or not.

[LETZRIDE]

What is your fuel pressure at key on engine off after the car has been sitting a number of hours? What is the fuel pressure at idle? and what is the fuel pressure when driving and under WOT? You said it is fine, but what are the numbers? Don't diagnose fuel pressure by wideband numbers.

Check all of your wiring - spark plug / fuel injector harness. Have you checked for vacuum leaks especially around your manifold? I know you had water getting into the engine on rain falls, maybe this is part of the problem with a vacuum leak?

How old are your plugs/wires/coils?

[ssms5411]

Plugs, wires, coils ,icm is all new. Fuel pressure is 44psi at idle, goes up alittle when I rev it. Will check wot tomorrow when i take it out, was out just a bit ago looking at the lights on the gauges and check for codes and the po1107 came back so im stumped with the map codes.

[LETZRIDE]

PO107 is a manifold absolute pressure/Barometric pressure circuit Low Input

From https://www.obd-codes.com/p0107

Symptoms include:

• Hard to start
• Long cranking times Sputtering/missing
• Blowing black smoke
• Poor fuel economy
• Dies intermittently MIL(Malfunction Indicator Lamp) illumination

Causes:

• Bad MAP sensor
• Open or short in the signal circuit
• Open or short in the 5 Volt reference circuit
• Ground circuit open or shorted
• Bad PCM

Solutions:

First, using a scan tool with the Key on and engine running, monitor the MAP sensor voltage. If it is reading less than .5 volts, turn engine off, unplug the MAP sensor and, using a DVOM (Digital Volt/Ohm Meter) check for 5Volts on the 5 Volt reference circuit. - You said you did this and had 5 volts? See below as you need to check two spots:

1. If there is not 5 Volts on the reference circuit, then check for the reference voltage at the PCM connector. If it is present at the PCM connector but not the MAP connector, repair the open in the reference circuit between the PCM and MAP harness connector. If 5 Volt reference is NOT present at the PCM connector, check powers and grounds of PCM and repair/replace as needed. (NOTE: On Chrysler products, a shorted Crank sensor, Vehicle speed sensor or any other sensor that utilizes the 5 Volt reference from the PCM can short out the 5 Volt reference. To fix simply unplug each sensor one at a time until the 5 Volt reference reappears. The last sensor unplugged is the shorted sensor.)
2. If you have a 5 Volt reference at the MAP connector, jumper the 5 volt reference circuit to the signal circuit. Now check the MAP voltage on the scan tool. It should be 4.5 to 5 Volts. If it is, replace MAP sensor. If not, repair open/short in the signal circuit wiring and re-check.
3. If all appears okay, perform a wiggle test. Start engine and manipulate the harness, connector and tap on the MAP sensor. Note any changes in voltage or engine speed. Repair connector, harness, or sensor as needed. - Steve I had this problem in my jeep and it took forever to diagnose with my EVAP sensor.
4. If the wiggle test checks out, use a vacuum pump (or just use your lungs) to draw a vacuum on the MAP sensor vacuum port. As you add vacuum the voltage should decrease. With no vacuum, the MAP sensor should read approximately 4.5 volts. If there is no change in MAP sensor reading on the scan tool, replace MAP sensor.

Did you test each of the 5 steps above? Since your MAP code is back I have a feeling you are wire related - that's your common piece in this all

[ssms5411]

Did you test each of the 5 steps above? Since your MAP code is back I have a feeling you are wire related - that's your common piece in this all

No, just the .5 volts on the map harness , ill check the others tomorrow, thanks again.

[ssms5411]

Car ran good no blinking ses light , fuel pressure at wot was 48-50 psi , not bad for a 16 year old Walbro 255 pump. So next thing im going to drive into the next city 35 miles one way to see how it does. Still checking on the map sensor.

[97rs4life]

a lot of guys back in the day would use hptuners and turn off the PO300 code so it never displays SES light when they cammed the car. The map sensor stuff though shouldn't be related to it. Could be a bad/corroded wire or spot in the harness giving you headaches.

[ssms5411]

Fixed the po300, was a vacuum leak, got a new harness and found my spare pcms so im going to try that.

[97rs4life]

awesome yea, those vacuum lines are getting a little "aged" by now haha

[LETZRIDE]

where was the vacuum leak located?

[ssms5411]

where was the vacuum leak located?

It was on the TB on 96's theres a big vac. Line where the evap connected to i had a rubber plug on it but it cracked and came completely off, i just filled the fitting with gasket maker, been doing awesome. Still trying to narrow down the map codes, have to pull the STB everytime I'm in there.

[ssms5411]

So replaced the pcm, still no luck. Will have to track down the short somewhere. Will try the steps Mike suggested, I hate to get in there though, its a killer on my back.

[ssms5411]

So im going to try jumping the circuit with a paper clip to see if im getting a input to the pcm, then ill check the ground while im at it, worse case scenario is ill have to run a wire or 2 from the pcm to the map.